CI: Add warnings & error on warnings

ci/build-posix.sh

@@ -1,5 +1,6 @@
 #!/bin/sh
-
+export CFLAGS="-Wall -Werror"
+export CXXFLAGS="-Wall -Werror"
 cmake -GNinja -Bbuild -DCMAKE_BUILD_TYPE=Release -DLIBICSNEO_BUILD_EXAMPLES=ON \
 	-DLIBICSNEO_BUILD_UNIT_TESTS=ON -DLIBICSNEO_ENABLE_TCP=OFF || exit 1
 

ci/build-windows.bat

@@ -4,8 +4,8 @@ mkdir build
 
 REM build
 cd build
-set CFLAGS=/WX
-set CXXFLAGS=/WX
+set CFLAGS=/WX /W4 /wd4127
+set CXXFLAGS=/WX /W4 /wd4127
 cmake -GNinja -DCMAKE_BUILD_TYPE=RelWithDebInfo -DLIBICSNEO_BUILD_UNIT_TESTS=ON -DLIBICSNEO_ENABLE_TCP=ON ..
 if %errorlevel% neq 0 exit /b %errorlevel%
 cmake --build .